In this April 20, 1999, file photo unidentified young women head to a library near Columbine High School where students and faculty members were evacuated after two gunmen went on a shooting rampage in the school in the southwest Denver suburb of Littleton, Colo., in Denver. (ASSOCIATED PRESS / /Kevin Higley, File)

WASHINGTON (AP) — Gun control advocates sputter at their own impotence. The National Rifle Association is politically ascendant. And Barack Obama’s White House pledges to safeguard the Second Amendment in its first official response to the deaths of at least 12 people in a mass shooting at a new Batman movie screening in suburban Denver.

Once, every highly publicized outbreak of gun violence produced strong calls from Democrats and a few Republicans for tougher controls on firearms.

Now those pleas are muted, a political paradox that’s grown more pronounced in an era scarred by Columbine, Virginia Tech, the wounding of a congresswoman and now the shootings in a suburban movie theater where carnage is expected on-screen only.

“We don’t want sympathy. We want action,” Dan Gross, president of the Brady campaign said Friday as President Barack Obama and Republican challenger Mitt Romney mourned the dead.

Ed Rendell, the former Democratic governor of Pennsylvania, was more emphatic than many in the early hours after the shootings. “Everyone is scared of the NRA,” he said on MSNBC. “Number one, there are some things worth losing for in politics and to be able to prevent carnage like this is worth losing for.”

Yet it’s been more than a decade since gun control advocates had a realistic hope of getting the type of legislation they seek, despite predictions that each shocking outburst of violence would lead to action.

In 1994, Congress approved a 10-year ban on 19 types of military-style assault weapons. Some Democrats quickly came to believe the legislation contributed to their loss of the House a few months later.

Five years later, Vice President Al Gore cast a tie-breaking Senate vote on legislation to restrict sales at gun shows.

The two events turned out to be the high-water mark of recent Democratic drives to enact federal legislation aimed at reducing gun violence, and some Republicans said they could see the shift coming.

“The news media in its lather to distort this whole issue may be wrong in their estimation that this will help Al Gore,” then-Senate Majority Leader Trent Lott, R-Miss., said in an Associated Press interview a few weeks after the tie-breaking vote. “As a matter of fact, it may already have hurt him, and it may hurt him a lot more.”

By 2004, when the assault weapon ban lapsed, congressional Democrats made no serious attempt to pass an extension. President George W. Bush was content to let it fade into history.

Public sentiment had swung.

According to a Gallup poll in 1990, 78 percent of those surveyed said laws covering the sale of firearms should be stricter, while 19 percent said they should remain the same or be loosened.

By the fall of 2004 support for tougher laws had dropped to 54 percent. In last year’s sounding, 43 percent said they should be stricter, and 55 percent said they should stay the same or be made more lenient.

In terms of electoral politics, Harry Wilson, a Roanoke College professor and author of a book on gun politics, said violent crime has been declining in recent years and, “It becomes increasingly difficult to make the argument that we need stricter gun control laws.”

Additionally, he said in some regions, gun control “can be a winning issue for Democrats. But nationally, it’s a loser ... and they have figured that out.” Attempts to emphasize the issue will “really motivate the opposition. And in a political campaign, nobody wants to do that,” he said.

At its core, Wilson said, the issue divides rural voters from urban voters.

Often, that means Republicans on one side, Democrats on the other. But not always.

In the current election cycle, the NRA has made 88 percent of its political donations to Republicans, and 12 percent to Democrats, according to OpenSecrets.org. The disparity obscures that the organization consistently supports some Democrats, a strategy that allows it to retain influence in both parties.

Its clout was vividly on display in 2010 when majority Democrats in the House sidetracked legislation giving the District of Columbia a voting representative in the House of Representatives. Republicans had vowed to add an NRA-backed provision invalidating a city ban on handgun possession as the price for passage, and there was little doubt it had the votes to prevail.

Later in the year, the NRA objected to legislation to require groups airing political advertising to disclose donors. Fearing the fallout, enough rank and file Democrats demanded changes that the leadership had to revise the bill. A revised bill, granting the NRA and other large organizations an exemption, eventually passed.

Dan Gross, head of the Brady Campaign to End Handgun Violence, says Democrats have drawn the wrong lessons for years. “The cultural narrative exists because of the assessment of Al Gore’s loss in 2000 and the mid-terms in 1994, and in both cases I think the gun issue was scapegoated,” he said. “Those who didn’t vote for Al Gore weren’t going to vote for him anyway.”

At the same time, Gross readily conceded the lingering hold of the issue.

“Look at Kerry when he felt he needed to dress up in hunting gear,” he said, referring to the Democratic presidential candidate’s well-photographed excursion into a duck blind in camouflage clothing in swing-state Ohio a few weeks before the 2004 election.

Four years later, Obama won the White House despite strong opposition from the NRA.

As a senator from Illinois and state lawmaker before that, he was a strong supporter of gun control.

Following last year’s killing of six people and the wounding of Rep. Gabrielle Giffords in Tucson, Ariz., Obama called for steps to “keep those irresponsible, law-breaking few from getting their hands on a gun in the first place.”

He advanced no legislative proposals then, and on Friday, spokesman Jay Carney said, “The president believes that we need to take common-sense measures that protect Second Amendment rights of Americans, while ensuring that those who should not have guns under existing law do not get them.”

Obama isn’t the only 2012 White House candidate to adjust his views on gun control.

In a losing Senate campaign in Massachusetts in 1994, Mitt Romney said, “I don’t line up with the NRA.” A decade later, as governor, he signed legislation making a state assault weapons ban permanent.

This year, bidding for support at the NRA convention, he said: “We need a president who will enforce current laws, not create new ones that only serve to burden lawful gun owners.”